Fig. 5.

A cartoon showing the early stages of the anthrax life cycle. Three proteins (immune inhibitor A, ●; GPR-like spore protease, ▲; and alanine racemase, ■) are thought to be involved in the spore germination/early outgrowth and macrophage interaction. It has been reported that GPR-like spore protease and alanine racemase play an important role in triggering the spore germination 11., 30., 33.. Immune inhibitor A may be discharged from dormant spores during the early stage of anthrax infection and facilitate anthrax invasion into host cells and escape the host immune system. These proteins may be excellent potential targets for vaccines or inhibitory drugs.